As we saw in the previous part of this series, Medical colics are those which can be managed medically, usually on the yard. However, about 1 in 10 cases of colic require emergency referral to an equine hospital for surgery.

This is what most horse owners are terrified of. The general indicators that a horse has a surgical colic are:

1) Heart rate over 60 that isn’t relieved by injectable painkillers.
2) Dilated loops of small intestine on rectal exam.
3) Positive stomach reflux from the stomach tube.
4) A definite rectal diagnosis of a surgical problem.
5) “Toxic rings” – dark red or purple gums, that indicate that the horse is going into toxic shock.

Of course, it varies between horses, and the vet has to make a judgment call based on all the evidence available.

We also have to talk to the (by now usually frantic) owners about costs. Colic surgery usually costs between £4000 and £5000, but can easily be a lot more. Even if the horse is insured, it is important to check how much the insurance company will cover – there are a couple of companies out there who will only cover part of the costs of emergency surgery. If in doubt, always call your insurer’s helpline.

However, colic surgery is one of the most genuine emergency operations there is – and it can be truly life-saving.

So, what causes a surgical colic? Probably the most common are:

1) Twisted bowel. If a length of bowel twists around itself, it can cut off the circulation. At this point, the gut begins to die, and unless it can be removed by surgery, and quickly, the horse will go into toxic shock and die. This commonly happens in the small intestine or occasionally the colon, but there’s also a condition where the caecum gets turned partially inside out (an intussusception).

2) Small intestinal blockages. Horses rarely eat things that get stuck in the small intestine (although it can happen). More commonly, a really heavy worm burden can simply block up the bowel; with the bowel overfull, the blood supply starts to fail, and the gut, again, can die. I once had a patient who was a little foal with a severe colic; we removed two gallons of worms from her small intestine!

3) Strangulating Lipomas. These are really common in older horses and ponies. A small, benign, fatty tumour forms somewhere in the abdomen, causing no harm at all. However, it grows on a stalk, and eventually, the stalk gets wrapped around a length of gut, cutting off the blood supply… This results in the bowel dying, as if it had twisted. Fortunately, these are usually really simple surgical procedures; unfortunately, older horses and ponies are less likely to be insured for surgery.

There are also a number of medical conditions that can mimic those requiring surgery – particularly peritonitis and anterior (or proximal) enteritis. Horses with these conditions are often referred for possible surgery because it’s very hard for the vet in the field or on the yard to be 100% certain they’re not surgical. I think that most of us would say it makes a lot more sense to have the horse at the hospital, with a surgeon on call, to make the definitive diagnosis, rather than waste time in the stable, and risk having to then decide it needs surgery when it’s still an hour or more away in travelling time from the hospital!

So, what happens when the vet decides that a colic case isn’t suitable for medical management?

Firstly, they’ll talk to you about the options. If a horse isn’t insured, or there’s no money for treatment, it is a perfectly respectable and responsible decision to decide, sadly, to put the horse to sleep rather than prolong its suffering.

Hopefully, of course, that won’t be the case. Once you and the vet have decided that referral is the way forward, your vet will get in contact with a referral hospital. If you’re very lucky, it will be one run by your vet’s practice, but in most cases, it will be a specialist referral hospital. I must say here that not every centre with surgical facilities is able to cope with emergency colic surgery – they need not only to have the facilities (knock-down box, operating theatre, recovery box etc), but also the staff (not only a surgeon, but also enough vets and nurses to take care of your horse in the vital recovery period). Your vet will have a list of suitable referral hospitals – generally, its best to send the horse to the closest one with the shortest transport time, but your vet will be able to advise you.

Making an emergency referral is simple – but only your vet can do it. A referral hospital will not accept referrals from the horse’s owner! Once you’ve made the decision to refer, your vet will call them and speak to the veterinary team on call, who will be available 24/7/365 (when I was part of one such team, we ALWAYS seemed to get our referrals at about 10pm!). They’ll let him or her know what they want done during transport – generally, they’ll describe what painkillers they want given, and what samples they want taken (don’t be surprised if your vet gives you a couple of blood tubes to take up and give to the referral team). In addition, they’ll sometimes ask the vet to put in a stomach tube and tie it in for the journey – this is to prevent the stomach from getting over-full and bursting if there’s an obstruction in the small intestine. Don’t forget your horse’s passport – legally, they do need it even when being rushed to emergency surgery.

Your vet will generally give you directions and a contact number for the hospital, and send you on your way. Remember, they can’t normally go with you, because your horse’s colic, while devastating, is probably only one of several cases they’ll have to deal with.

If there’s a problem (e.g. your horse getting distressed) in transit, call your vet or the referral number you were given – but if at all possible don’t stop unless they tell you to! Remember, you’re on your way to the best equipped help available.

On arrival at the hospital, you can expect to be met by the veterinary and nursing team. Your horse will be rushed to an assessment area, and you’ll probably be given a lot of scary-looking paperwork to sign. Generally, this comes into 2 parts – firstly, you’re signing to give consent for whatever they need to do (and remember, a lot of drugs aren’t technically licensed for use in horses, because the manufacturers haven’t paid for an official license for that drug in horses. It doesn’t mean a drug is dangerous or experimental, it’s probably used on a daily basis by the hospital. You’ll have to sign consent to use unlicensed medication – it’s absolutely routine, and nothing to worry about). Most hospitals will also ask to see your passport – if you haven’t got it, or it isn’t signed to mark the horse as “not intended for human consumption”, legally the hospital can refuse treatment (although they rarely do).

The second set of paperwork you’ll sign is a bit more pedestrian – you’ll be signing to say that you will pay for any treatment!

While you’re contemplating the paperwork, your horse will be undergoing another examination by the veterinary team. This is to establish what’s going on, and what’s changed since your vet examined him back on the yard. They may well repeat some tests – most colic conditions are dynamic (i.e. constantly changing), and sometimes the change is more useful in working out what’s going on than a one-off test. Other tests they may wheel out include ultrasound – the powerful ultrasound systems available in a hospital environment can give the vets a lot more information about what’s going on. The vets will then make a decision about what to do – don’t be disappointed or worried if they don’t rush immediately to surgery! They may decide to try a course of medical treatment first (remember, they don’t have to rush as much as your vet does – if your horse’s situation deteriorates, they can operate at a moment’s notice).

In many cases, however, they will decide to take the horse straight to theatre. If so, you normally won’t be able to follow, so I’m going to describe what happens once you’ve been gently steered in the direction of a waiting room.

To begin with, the horse will have an intravenous catheter fitted, to allow easy access for fluids and drugs. A horse with colic is systemically weakened, so will almost invariably be given intravenous fluids during surgery. He’ll then be given a premed – this is a sedative, designed to make induction into anaesthesia gentler. It will usually contain the drug acepromazine, because the use of this before surgery has been demonstrated to reduce the risks of anaesthetics.

He’ll then be led into a knock-down box: this is a special padded room, designed to make induction of anaesthesia safer. Then he’ll be anaesthetised with an injection containing (usually) a mixture of 2 anaesthetic agents, ketamine (no, it’s not a tranquilizer, it’s an anaesthetic) and diazepam or a similar drug. Shortly after the injection, he’ll go wobbly, and then quickly lie down.

Once he’s asleep, the team will swing into action: a tube will be passed down his throat to help him breathe and he’ll be moved into the operating theatre. While this was going on, the surgeon(s) will have been scrubbing up, ready to start.

Once he’s in theatre and safely ensconced on a well cushioned table (to prevent pressure sores etc), he’ll be put onto anaesthetic gas to keep him asleep.

The surgery involves a long incision down the midline of the belly. The surgeons can then have a good look through all the intestines, to find the problem. This is the exciting, sexy bit, but it’s actually pretty simple in principle: “if in doubt, cut it out”. In other words, removing devitalized (dead) bowel, emptying out anything in the bowel that shouldn’t be there (e.g. a caecal impaction), replacing anything that’s got stuck in the wrong place (e.g. an entrapment) and untwisting anything that’s tied up. There are usually at least 2 surgeons, because one person is needed to hold loops of intestines (and they don’t stay still – sometimes they wriggle around in your arms)! Meanwhile, the anaesthetist will be carefully monitoring all sorts of parameters (heart rate, blood pressure, ECG, reflexes, breathing and blood gasses can all be monitored at many hospitals) and adjusting the anaesthetic and any other drugs to give the safest and most effective anaesthetic.

Once whatever the problem was has been found and (hopefully) sorted out, your horse will be returned to the recovery room. In many ways, this is the most dangerous part of the procedure. Horses are very prone to breaking things when they wake up, so everything is done to keep it as calm and quiet as possible. Sometimes, the veterinary team will help the horse to rise, using hoists and lifts; other times, it works out better to let him get up in his own time. In either case, he will be moved into a padded room, and left in dim light, as quietly as possible, so he wakes up slowly.

Once awake, and steady on his feet, he’ll be moved to an intensive care box; he’ll almost certainly be on a drip to keep him hydrated. At regular intervals through the next 24 hours (or longer) he’ll be checked by vets and nurses. In some cases, the guts don’t start working properly on their own, and medication may be needed to encourage motility (e.g. a lidocaine drip). Although everyone gets excited about the surgery, it is this recovery period that is in many ways the most important in getting a good long-term prognosis.

As time goes on, the vets and nurses will try and tempt the horse to eat – normally, we’ll try and get him eating fresh grass as soon as possible. As soon as he is stable enough and eating on his own, he’ll be sent home – most horses do better in their own home environment, so as soon as they no longer require advanced medical intervention, they can go home. Once home, it’s important that the discharge instructions from the hospital are followed – it can be tempting to try and speed things up, but don’t rush it! Major abdominal surgery takes time to recover from.

Colic is a worrying condition to have to deal with as an owner, especially as it often seems to come out of the blue. However, if you ever have to go through it, I hope that having read these blogs, you’ll have some idea of what’s being done, and why. Remember, our aim as vets is to help your horse and, if at all possible, send him home to you fit and well.

If you are worried your horse or pony may be suffering from colic, talk to your vet, or check the symptoms using our Interactive Equine Symptom Guide to help assess how urgent the problem may be.